3. Principles and concepts of cropping systems – Contd.

Transcript

Hi friends during the last lecture, I have introduced you to the different cropping systems and examples also, how the cropping systems can be selected. In this lecture we will be studying what are the cropping interactions and also crop management studies, on those cropping systems. Coming to the inter-cropping, which is one of the type of the multiple-cropping, let us study what is the crop interaction in these intercropping systems.

• The interaction between the component crops may be competitive, non-competitive or complementary. In this case, as you know, two or more crops are grown at a time. The competition may be competitive or non-competitive or maybe complementary. These types of interactions will exist.
• Then coming to the combination of tall and short, then short and long duration reduces the competition for sunlight. There may be competition for sunlight. How it will be managed? By selecting a tall and short crop. Tall statured and a short statured crop should be selected. Or duration wise also. Short and long duration varieties can be selected to avoid the competition for sunlight.
• Then coming to the third one. Water is used very efficiently by the crops. That extract water from the different soil depths due to different rooting depths, or produce more canopy thus reducing the evaporation from the soil surface. So when we do select a tall growing crop along with a short growing, and also a short duration and a long duration crop in union, then what happens; these crops extract the moisture from the different soil depths. Then there will be no competition for water or the moisture.
• Then the fourth one. Combination of cereal and legume crop reduces the input of nitrogen. As you all know, legume crops are good nitrogen fixers in the soil. So in case of inter-crops, in all the cases; in almost all the cases, a cereal and a legume combination will be selected, so as to reduce the burden on the nitrogen.

Coming to the sequential cropping. What type of crop interaction exists in case of sequential cropping.

• The interaction is non-competitive. So here there is no interaction, because as you know sequential cropping is; the crops are grown in succession, one after the other. So there will be no interaction. There will be no competition. The competition is non-competitive.
• So second one is, the preceding crops have an allelopathic effect on the succeeding crops. This is in case of the crop which is grown first will have some allelopathic effect on the succeeding crops. Allelopathic means extradition of some chemicals into the soil, which when the succeeding crop is being sown will affect the crop growth and yield of the crop. So some preceding crops have an allelopathic effect on the succeeding crops.
• The soil fertility is reduced by the preceding crop. Whatever the crop that is sown in the kharif season. That soil fertility, hence it a high feeder of nutrients. So that will affect the soil fertility of the succeeding crop.
• The residual effect of farm yard manure or phosphorous fertilizer can be seen on the succeeding crop. In case of sequential cropping whatever the fertilizer or the farm yard manure or the organic manure, which is applied to the first crop in a sequence. That will have an effect and that effect will be obtained by the second crop in a sequence.

So these are the interactions that will take place in case of sequential cropping.

Then coming to the crop management. How the crop should be managed by the cropping system, because we are having two or three crops at a time.

• So first and foremost is use less competitive crops. I have already told you the less competitive crops. The crops which are highly competitive should not be selected. So use, you have to select a crop, which are less competitive in nature.
• Then adjust the time of sowing in staggered planting in aggressive and non-aggressive crop combination. So in case of inter-cropping, two or three crops are being sown. So we have to go for staggered sowing practices. That means, one crop is sown, after that a few days later a second crop is sown. So this is what a second staggered cropping; staggered sowing should be followed.
• Third one is nutrient application as per the requirement of the component crop. When the both the crops are grown. When the both the recommendations are different, what should we do. So in case of fertilizer recommendation, we should go for the recommendation of the component crops also.
• Then weed control. Less weed infestation compared to mono-crops. When compared to monocrops, in case of inter-cropping, the weed competition or the weed growth will be very less, because the inter-cropping, the inter-distance or the rows, the distance between the rows will be occupied by the second crop. So there will not be any chance, there will not be any opportunity for the weeds to grow and establish. So the weed control here, the weed growth is very minimal as compared to mono-crops.
• Then pest and disease control. Less pests and diseases due to crop diversity. In case of intercropping we are using two to three crops at a time. So as such the diversity will be more. Because of the diversity; higher diversity, the pest and diseases attack will be very less.

Coming to the crop management in case of sequential cropping.

• In case of sequential cropping we have to use short duration and photo insensitive varieties. Since in the sequential cropping, the crop will be grown in succession, that is one after the another. There will not be any succession, so we should use only the short duration and photo insensitive varieties. The short duration varieties will complete the life cycle very early, and also photo insensitive means the crop can be grown in any part of the season.
• Then harvest first crop at physiological maturity to avoid the terminal drought of the second crop. So the time has to be adjusted because here the two crops are growing in succession. So in that case we have to harvest the first crop at physiological maturity, so that most time will be available for the completion of the life cycle of the second crop. So the second crop should be avoided in the terminal drought.
• Add additional amount of N if the preceding crop is sorghum or millet. If the preceding crop belongs to cereal or a millets, we have to give an additional fertilizer dose for the succeeding crop in the case of sequential cropping.
• Then reduce the N quantity if the preceding crop was a legume. If at all the preceding crop was a legume. Since the legume crops are self nitrogen fixers. So for the succeeding crop the nitrogen amount can be reduced substantially.
• If the FYM or P fertilizers are applied to the preceding crop, reduce the input of N and P to the succeeding crop. In a same also FYM and phosphorous are applied to the preceding crop. That much amount of phosphorous and FYM can be curtailed, or can be cut down for the succeeding crop.

So the in a conclusion, the plant characteristics that influence the cropping system are the plant height, the plant canopy, nutrient and water requirements, root structure and plant products. So these are all the characteristics one should look into that while deciding a cropping system for that region. Second is farm sustainability. The farm sustainability depends on the efficient use of natural resources, depending on the requirements of the farmers. The farm sustainability has to be there. The farm sustainability depends upon the resources like soil, water, energy and the plant diversity. And the third one is a sustainable system aims to optimize the production, rather than maximizing it. In case of cropping system we are not aiming at the maximizing the production. But at the same time we are aiming at the optimization. So in case of crop systems, our goal, our aim is not to maximize the production, but to optimize the production by utilizing optimal utilization of all the available resources.

So in this way the cropping systems have to be selected, based on the certain characteristics and the features of crops and varieties for successful production and also successful productivity of the cropping systems for that region.

Thank You.